The strategy of
myasthenia gravis has been progressed during recent 30 years. Extended
thymectomy and alternate-day
prednisolone administration remarkably improved
therapeutic effect in
myasthenia gravis. Besides of these
therapies,
plasmapheresis and immunoadsorption
plasmapheresis extremely improved mortality in
myasthenia gravis. 1.
Corticosteroid therapy Usually initial doses of PSL is 20-30 mg every other day in the morning after
thymectomy, and increased 5 mg every on-day. Maximum PSL doses is 80-100 mg alternate-day, then this doses will be maintained over 4 weeks. After these procedures, PSL is gyradually decreased and discontinued within 2-3 years. 2.
Thymectomy Extended transsternal
thymectomy is the most useful method, because many authors have reported that re-
thymectomy reveals re-appearance of thymus. 3. Invasive
thymoma Although this type of
thymoma has been called malignant
thymoma, it should be called as invasive
thymoma since any
thymoma can invade surrounding tissues for a long subclinical period. Strategy of treating invasive
thymoma is PSL administration, radiation and
chemotherapy.
Chemotherapy should be performed depend on histopathological findings of
thymoma. CHOP
therapy is useful for the lymphocytic cell predominant type of
thymoma, however CHOP + cis-platin
therapy is useful for the epithelial cell predominant type. Treatment of
myasthenia gravis has been improved, however it is still unclear that how to treat invasive
thymoma, and how to prevent re-appearance of symptoms by decrease or discontinuity of PSL administration.